I get aggravated when I have to go shopping for groceries. People, by and large, are so inconsiderate. Turn the corner to go down an aisle, and someone will be ahead of me, walking down the middle of an aisle, then stop right there...and stare at the soup selections like a monkey doing a math problem. No...don't have any spacial awareness...just stop right there and hold up traffic while you decide which brand of chicken soup you want...and then act shocked that there is someone around you or act shocked that you...just somehow wound up blocking the entire aisle.
That's the type of behavior that makes me do the bulk of my shopping, when I can, after midnight. At that time, I only have to deal with the other shut-ins, and the shut-is are far more polite and considerate than "normal" people.